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Sediment transport mechanisms and selective removal of soil particles under unsteady-state conditions in a sheet erosion system

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International Journal of Sediment Research 2022年第2期37卷 151-161页

作者： Elham Sirjani Majid Mahmoodabadi Artemi Cerdà department of Soil Science Faculty of Agriculture Shahid Bahonar University of Kerman departament de geografia Universitat de València

Selective removal of particles and nutrients by water erosion is a key factor in soil erosion *** agricultural soils are located on gentle slopes where fertility is high;however,until now,the main attention on sediment transport mechanisms was paid to high-slope gradients,where soil erosion is intense,but soils are less *** the importance of sediment size distribution(SSD) and transport mechanisms under unsteady-state conditions,few studies have been done on this *** sediment concentrations in the early stages of the runoff indicate the need to deal with unsteady-state *** address this issue,sheet erosion experiments were done using a 0.2 m by 1 m tilting flume under controlled laboratory *** inflow rates(75,100,125,150,175,and 200 mL/s) were applied on two contrasting soils,including an adjacent agricultural soil and a not cultivated soil(namely Cropland soil and Control soil,respectively) at two low slope gradients(1.5% and 2%).No rill formation was observed during the *** sediment-laden runoff was sampled during unsteady-state flow to determine the SSDs and sediment transport mechanisms of eroded particles for unsteadystate *** results indicated different trends in the selective removal of sediment particles depending on hydraulic conditions and soil aggregate *** contribution of suspension-saltation(SS)to the total sediment load for the Cropland and Control soils varied from 22% to 68% and from 35% to 59%,respectively,while up to 78% and 65% of soil particles were transported by bed load(BL),***,SS and BL indicated a reverse trend with stream *** Cropland soil showed a single peak in the SSD at low stream powers because of the selective removal of fine particles(0.042 mm),whereas the SSD was shifted to a bimodal distribution at higher stream powers with the selective depletion of both fine(≤0.084 mm) and coarse(1.5 mm) *** Control soil experienced a

关键词： Aggregate breakdown Bed load Stream power Suspension-saltation Tilting flume

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Multitemporal landslide inventory analysis of an intertropical mountain in west-central Mexico——Basis for hazard management

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Journal of Mountain Science 2022年第6期19卷 1650-1669页

作者： Alejandro Cesar VALdeS CARRERA Manuel E.MENDOZA Teodoro CARLÓN ALLENde Jose Luis MACIAS Centro de Investigaciones en geografia Ambiental Universidad Nacional Autonoma de MexicoMorelia 58190Mexico Consejo Nacional de Ciencia y Tecnologia-Instituto de Geofisica-Unidad Michoacan Universidad Nacional Autonoma de MexicoMorelia 58190Mexico Instituto de Geofisica-Unidad Michoacan Universidad Nacional Autonoma de MexicoMorelia 58190Mexico

Landslides in intertropical mountainous areas of Mexico are a natural hazard that could potentially generate a disaster. despite this, many areas lack landslide inventories, making it difficult to monitor and efficiently manage the associated risks for local populations. For this reason, the aim of this research was to undertake a multitemporal landslide inventory and analyze its conditioning factors in the Pico de Tancítaro stratovolcano, which, in recent decades, has presented several high-risk geomorphological events with disastrous consequences for nearby localities. The spatial distribution of landslides and its conditioning factors were mapped at a 1:50,000 scale for the 1995-2020 period, through visual interpretation of orthophotos and satellite images(Landsat, SPOT, and SENTINEL). The conditioning factors that link the most to landslides were Quaternary andesite and basaltic andesite rocks;volcanic cones, mountain river valleys, and very steep to steep slopes(30° to >45°), oriented to the South, North, and East;Andosols and Leptosols;and the oyamel fir and mixed forests. 505 landslide events classified into slides and flows that occurred in 1995, 2004, 2010, and 2015 were identified. New scars generated by the reactivation of landslide processes were also observed. The landslides in the study area were triggered by torrential rains caused by hurricanes and tropical storms;such as hurricanes Alex and Patricia. The inventory and analysis of conditioning factors highlighted the distribution and dynamics of slides and flows in the study area. In addition, the most important factors for studies of landslide susceptibility, hazards, and risks in the Pico de Tancítaro stratovolcano were identified, contributing to the management of geomorphological risks in intertropical mountain areas.

关键词： Geomorphology Mass wasting Natural hazards Pico de Tancítaro stratovolcano Risk management

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developing spatially and thematically detailed backdated maps for land cover studies

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International Journal of Digital Earth 2017年第2期10卷 175-206页

作者： Juan JoséVidal-Macua Alaitz Zabala Miquel Ninyerola Xavier Pons dep geografia Grumets Research GroupUniversitat Autònoma de BarcelonaBellaterraCataloniaSpain dep Biologia Animal Vegetal i EcologiaGrumets Research GroupUniversitat Autònoma de BarcelonaBellaterraCataloniaSpain

Global or regional land cover change on a decadal time scale can be studied at a high level of detail using the availability of remote sensing data such as that provided by ***,there are three main technical challenges in this ***,the generation of land cover maps without reference data is problematic(backdating).Second,it is important to maintain high accuracies in land cover change map products,requiring a reasonably rich legend within each ***,a high level of automation is necessary to aid the management of large volumes of *** paper describes a robust methodology for processing time series of satellite data over large spatial *** methodology includes a retrospective analysis used for the generation of training and test data for historical periods lacking reference *** methodology was developed in the context of research on global change in the Iberian *** this study we selected two scenes covering geographic regions that are representative of the Iberian *** each scene,we present the results of two classifications(1985-1989 and 2000-2004 quinquennia),each with a legend of 13 *** overall accuracy of over 92%was obtained for all 4 maps.

关键词： Land cover mapping Landsat statistical classifiers backdating Iberian Peninsula

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Earth observations for sustainable development goals monitoring based on essential variables and driver-pressure-state-impactresponse indicators

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International Journal of Digital Earth 2020年第2期13卷 217-235页

作者： Joan Masó Ivette Serral Cristina Domingo-Marimon Alaitz Zabala CREAF Grumets Research Group CREAFEdifici C.Universitat Autònoma de BarcelonaBellaterraCataloniaSpain dept.geografia Grumets Research GroupEdifici B.Universitat Autònoma de BarcelonaBellaterraCataloniaSpain

In recent years,researchers of different communities have increased their efforts in formalizing a set of measurements regularly collected for analysing changes in Drivers,States,Impacts and Responses of a given *** some cases,different actors have converged in a minimum set of Essential Variables(EVs),such as for Climate,Biodiversity or *** definition of such EVs is an ongoing evolution and in extension(*** for water)although some communities have not even started(*** and energy).This paper characterizes the Earth Observation(EO)networks and creates a graph representation of their ***,this graph is enriched with the EVs produced by each network creating a knowledge ***,an effort has been done to identify links between EVs and Sustainable development Goals(SDG)indicators in a way that they indirectly connect the *** analysis to detect gaps in EO variables due to a lack of observational networks is *** suggestions for improving SDG indicators framework by considering EVs are exposed,as well as proposing new necessary EVs and suggesting new EO based *** complete graph is available in the ENEON website(http://***/graphev-sdg/).

关键词： Gap analysis policy monitoring essential variables earth observation

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Social Accounting Matrix on the Base of the Mexican System of National Accounting

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Economics World 2016年第3期4卷 111-127页

作者： Dora Elena Ledesma-Carrion Lidia Hernandez-Hernandez Maria Teresa Leonor Mucino-Porras Instituto Nacional de Estadistica y geografia Ciudad de Mexico Mexico

Links between institutional sectors and economic activities with National Accounting System of Mexico are studied used accounting multipliers. Key sectors had changed to strategic or leading as oil and gas extraction and dairy product manufacturing, i.e., Mexico went from a producer of goods to a service provider country, losing value added in their production chains. The mixed income is leading/independent economic activity for woman whose income is between 1 and 5 minimum wages. This is really important in the domestic economy through its impact on solidarity activities： providing care and support and providing food. Moreover, non-financial corporations and households of 10 or more minimum wages for income investing in strategic sectors such as retail trade and wholesale and manufacturing products derived from oil and coal. This is evidence of two Mexicos： the traditional and industrialized.

关键词： social accounting matrix national accounting linkages accounting multipliers input-output tableau

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High-resolution patterns of palaeoenvironmental changes during the Little Ice Age and the Medieval Climate Anomaly in the northwestern Iberian Peninsula

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Geoscience Frontiers 2020年第5期11卷 1461-1475页

作者： Daniel Castro Martin Souto Maria Isabel Fraga Eduardo Garcia-Rodeja Sebastian Perez-Diaz Jose Antonio Lopez Saez Xabier Pontevedra-Pombal Dpto.Botanica Fac.BioloxiaUniversidade de Santiago de CompostelaGaliciaSpain Dpto.Edafoloxia e Quimica Agricola Fac.BioloxiaUniversidade de Santiago de CompostelaGaliciaSpain Dpto.geografia Urbanismo y Ordenacion Del TerritorioETS CaminosCanales y PuertosUniversidad de CantabriaSpain GI Arqueobiologia Instituto de HistoriaCCHS–CSICMadridSpain

to identify plant macrofossils,estimate peat humification and calculate hydroclimatic indices based on current bog species,with the overall aim of determining the climate conditions associated with evolution of the bog during the Medieval Climate Anomaly and the Little Ice *** proxies,together with historical and climate data,proved to be good indicators of the changes in bog surface ***:of the core led to identification of 9 different periods:two corresponding to the so-called Medieval Climate Anomaly(930 to 1345 AD,1075–665 calibrated years before present[*** BP]);four corresponding to the Little Ice Age(1345 to 1905 AD;665–105 cal yr BP);and three corresponding to the last century(1905 to 2000 AD).The findings revealed a generally dry climate that lasted until the 14th century,followed by a transition to a long period with a more humid,but characteristically very variable climate,which ended at the beginning of the 20th century and was followed by a rapid transition to more humid conditions and finally,a change to drier *** Medieval Climate Anomaly was indicated by the abundance of dry-adapted mosses(Leucobryum glaucum,Hypnum cupressiforme)and characterized by warm dry conditions and high levels of peat humification,with alternating wet *** LIA period was dated by a large abundance of Sphagnum species(an indicator of wetness)and a gradual increase in the humification ***,four different climate phases were differentiated in this ***-resolution reconstruction of the evolution of the CVM bog and the multiproxy approach have together enabled a more detailed identification of climatic variations in this area,which are generally consistent with the global models,as well as better definition of the elusive climatic oscillations in the last millennium and confirmation of the importance of local modulation of global *** study provides new information and a detailed chronology of climatic events that will hel

关键词： Last millennium Raised bog Plant macrofossil Humification analysis Southwest Europe Climate change

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10-Years Land Use Changes decrease Landscape Integrity in a Brazilian Hydrographic Basin

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Journal of Geographic Information System 2017年第2期9卷 221-243页

作者： Luciana S. Estevam Julia Arieira Peter Zeilhofer Débora F. Calheiros Enviromental Sciences Universidade de Cuiabá (UNIC) Cuiabá Brazil departamento de Ciências Ambientais Universidade de Cuiabá (UNIC)Cuiabá Brazil Instituto de geografia História e Documenta&ccedil &atilde o Departamento de Geografia Universidade Federal de Mato Grosso (UFMT) Cuiabá Brazil Instituto de geografia História e Documenta&ccedil &atilde o Departamento de Geografia Universidade Federal de Mato Grosso (UFMT) Cuiabá Brazil. Embrapa Pantanal Corumbá Brazil

Changes in land use associated with the suppression of native vegetation can greatly alter the landscape configuration, affecting biodiversity and environmental services availability. This study analyzes how changes in land use affect landscape patterns of vegetation remnant over a 10 year period. We quantified spatial landscape patterns throughout a hydrographic basin for the years 2002, 2008, 2010 and 2012, using nine landscape metrics. An indicator of integrity was used to details the transformation processes occurring in the basin that could be used to monitor the impact of landscape changes and its spatial patterning. Results showed that over this decade, extension of farming activities reduced the cover of native vegetation by 4.4%, with grassy-woody savanna, wooded savanna and forested savanna impacted especially strongly. Suppression of vegetation across this period reduced the size of fragments and their connectivity. The landscape fragmentation indicator indicated that the fragmentation pattern varied spatially, with the upland areas along river headwaters, being most fragmented. Areas of floodplains vegetation, belonged to the Pantanal Wetland, although in better integrity states, are the most threatened by current pressures of land use change. An intense recovery program for headwaters and aquifer recharge areas, as well as riparian forests, is recommended to avoid the future depletion of water production. Besides, we also recommend the maintenance and recovering of the connectivity of the current remaining patches of natural vegetation corridors and elaboration of specific laws that incoporate the consolidated scientific knowladge about wetland ecosystem functioning, like the Pantanal.

关键词： Connectivity GIS Metrics Catchment Area Fragmentation Remnant Vegetation

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Mid and late Holocene forest fires and deforestation in the subalpine belt of the Iberian range,northern Spain

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Journal of Mountain Science 2016年第10期13卷 1760-1772页

作者： Jose M.GARCIA-RUIZ Yasmina SANJUAN Graciela GIL-ROMERA Penelope GONZALEZ-SAMPERIZ Santiago BEGUERIA Jose ARNAEZ Paz COBA-PEREZ Amelia GOMEZ-VILLAR Javier ALVAREZ-MARTINEZ Noemi LANA-RENAULT Estela PEREZ-CARDIEL Carlos LOPEZ de CALLE Instituto Pirenaico de Ecologfa Consejo Superior de Investigaciones Cientificas(IPE-CSIC)Campus de Aula DeiP.O.Box 13.03450.080-ZaragozaSpain Estacion Experimental de Aula dei Consejo Superior de Investigaciones Cientificas(EEAD-CSIC)Campus de Aula DeiP.O.Box 13.03450.080-ZaragozaSpain Area of Physical Geography University ofLa Rioja26.004-LogronoSpain Centro de Investigaciones en geografia Ambiental Universidad Nacional Autonoma de MexicoUnidad MoreliaAntigua Carretera a Patzcuaro 870158190-MoreliaMichoacanMexico departamento de geografia y Geologia Faeultad de Filosofia y LetrasUniversidad de LeonCampus de Vegazana24.071-LeonSpain departamento de Ingenieria Agricola y Forestal Universidad de ValladolidCampus La Yutera34.071-PalenciaSpain department of Geography and Land Management University of Zaragoza50.009-ZaragozaSpain Freelance archaeologist Auda.Colon426003-LogronoSpain

The conversion of subalpine forests into grasslands for pastoral use is a well-knownphenomenon, although for most mountain areas the timing of deforestation has not been determined. The presence of charcoal fragments in soil profiles affected by shallow landsliding enabled us to date the occurrence of fires and the periods of conversion ofsubalpine forest into grasslands in the Urbión Mountains, Iberian Range, Spain. We found that the treeline in the highest parts of the northwestern massifs of the Iberian Range(the Urbión, demanda, Neila, and Cebollera massifs) is currently between 1500 and 1600 m a.s.l., probably because of pastoral use of the subalpine belt, whereas in the past it would have reached almost the highest divides(at approximately 2100–2200 m a.s.l.). The radiocarbon dates obtained indicate that the transformation of the subalpine belt occurred during the Late Neolithic, Chalcolithic, Bronze Age, Iron Age, and Middle Ages. Forest clearing was probably moderate during fires prior to the Middle Ages, as the small size of the sheep herds and the local character of the markets only required small clearings, and therefore more limited fires. Thus, it is likely that the forest recovered burnt areas in a few decades; this suggests the management of the forest and grasslands following a slash-andburn system. During the Middle and Modern Ages deforestation and grassland expansion affected most of the subalpine belt and coincided with the increasing prevalence of transhumance, as occurred in other mountains in the Iberian Peninsula(particularly the Pyrenees). Although the occurrence of shallow landslides following deforestation between the Neolithic and the Roman Period cannot be ruled out, the most extensive shallow landsliding processes would have occurred from the Middle Ages until recent times.

关键词： Forest fires Holocene Subalpinegrasslands Shallow landslides Landscape changes Iberian Range

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Assessment of Physical Vulnerability in Santo Domingo de Heredia, Costa Rica, Central America

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World Journal of Engineering and Technology 2014年第3期2卷 78-84页

作者： Jonnathan Reyes Chaves Mario Fernandez Arce Daniel Solis Rafael Bolanos Villalobos Escuela de geografia Universidad de Costa Rica(UCR Preventec-Universidad de Costa Rica(UCR) Escuela de Geografia-UCR and Centro de Investigaciones en Ciencias Geologicas-UCR Preventec-UCR Casa de la Cultura de Santo Domingo de Heredia

This work assesses the physical vulnerability of the Santo Domingo Canton in the province of Heredia in Costa Rica. We evaluate the vulnerability of areas located in high risk zones as well as the structural resistance of structures of the canton and then combine them to obtain an index of Physical Vulnerability. Most of the communities in high risk areas in this Canton have not been properly identified and mapped. This identification and mapping will enhance the management of disaster risks, reduce the infrastructure vulnerability and protect vulnerable families in there. We created an index ranging between 0 and 1 for each indicator of physical vulnerability (human settlements in areas of high risk and structural resistance) and another similar index resulting from the combination of vulnerability information from both indicators. The greater part of the territory of Santo Domingo has low physical vulnerability but there are critical sites in the West and the East of the canton.

关键词： Vulnerability Santo Domingo Heredia Disasters Prevention Costa Rica

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SUOLI A STRISCE PARALLELE IN VALFURVA(ALTA VALTELLINA)

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Natural Disaster Reduction in China 1987年第1期 217-222页

作者： CLAUDIO SMIRAGLIA Istitutodi geografia dell’Università Cattolica di Milano

Slopes with sorted strips in Valtellina(Sondrio-Northern Italy).Some slopes with sortedstrips were observed at the edge of two glaciers of Valfurva(upper Valtellina).Some informations onthe morphology and the sedimentology of the sorted strips discovered near the Zebrùglacier are givenin *** length is on an average of 2.2 metres and their inclination ranges from 14°to 24°.

关键词： Pi SUOLI A STRISCE PARALLELE IN VALFURVA ALTA VALTELLINA

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